Condensed Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating Activities
Net income	$ 251,092	$ 136,450
Loss from discontinued operations	0	42,704
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other	106,266	97,403
Stock-based compensation expense	91,567	75,487
Deferred income tax expense	5,756	56,584
Effects of exchange rate changes on monetary assets and liabilities denominated in foreign currencies	6,021	(6,049)
Other non-cash items	5,166	7,812
Total adjustments to reconcile net income to net cash provided by operating activities	214,776	231,237
Changes in operating assets and liabilities, net of the effects of acquisitions:
Accounts receivable	182,469	140,471
Inventories	(6,645)	(1,398)
Prepaid expenses and other current assets	(38,080)	(5,957)
Other assets	1,795	(9,597)
Income taxes, net	(72,405)	(73,567)
Accounts payable	19,851	(9,272)
Accrued expenses and other current liabilities	10,435	(20,536)
Deferred revenues	(41,100)	26,084
Other liabilities	5,850	(790)
Total changes in operating assets and liabilities, net of the effects of acquisitions	62,170	45,438
Net cash provided by operating activities of continuing operations	528,038	455,829
Net cash used in operating activities of discontinued operations	0	(56,070)
Net cash provided by operating activities	528,038	399,759
Investing Activities
Purchases of available-for-sale investments	(332,136)	(590,004)
Proceeds from sales of available-for-sale investments	434,901	562,098
Proceeds from maturities of available-for-sale investments	196,791	179,330
Purchases of property and equipment	(32,929)	(38,650)
Cash paid for acquisitions, net of cash acquired	(65,983)	(60,449)
Cash paid for licensing agreements and technology	(1,217)	(5,155)
Other	3,002	987
Net cash provided by investing activities of continuing operations	202,429	48,157
Net cash used in investing activities of discontinued operations	0	(3,891)
Net cash provided by investing activities	202,429	44,266
Financing Activities
Proceeds from issuance of common stock under stock-based compensation plans	113	1,490
Proceeds from credit facility	0	125,000
Repayment of credit facility	0	(95,000)
Repayment of acquired debt	(5,674)	(4,000)
Stock repurchases, net	(764,978)	(500,000)
Cash paid for tax withholding on vested stock awards	(49,936)	(60,547)
Transfer of cash to GoTo Business resulting from the separation	0	(28,523)
Net cash used in financing activities	(820,475)	(561,580)
Effect of exchange rate changes on cash and cash equivalents	(3,414)	5,370
Change in cash and cash equivalents	(93,422)	(112,185)
Cash and cash equivalents at beginning of period, including cash of discontinued operations of $0 and $120,861, respectively	1,115,130	956,956
Cash and cash equivalents at end of period	$ 1,021,708	$ 844,771